Electronic relay



Feb. 16, 1937. 5 BARUCH 2,071,057

ELECTRONIC RELAY Filed Feb. 9, 1952 IN ENTORZ Z ATTORN EY Patented Feb. 16, 1937 UNITED STATES ELECTRONIC RELAY Sydney N. Baruch, New York, N. Y., assignor, by mesne assignments, to Nortron Patents Corp, New York, N. Y., a corporation of New York Application February 9, 1932, Serial No. 591,911

38 Claims.

This invention relates to an electronic relay and more particularly to a low-gas-pressure tube adapted for the rectification of alternating current energy and the inversion of direct current energy into alternating current or interrupted direct current energies.

It is an object of my invention to provide an electron relay which is capable of operation at high power capacities, at the same time experiencing a negligible power loss.

It is a further object of the invention to assure stability in the operation of the device.

Furthermore the ruggedness of the structure eliminates the possibilities for the break-down of the elements.

Other objects and purposes will appear from the more detailed description of a preferred embodiment of my invention taken in conjunction with the accompanying drawing, in which:

Fig. l is an elevation partly in section of one form of my invention.

Fig. 2 is an elevation partly in section of a corresponding form of my invention employing a different arrangement of the heating elements.

Fig. 3 shows in detail a partial sectional view of the tube structure at the anode end of the tube, with a detail of the circuit connections.

Fig. 4 shows in section a modified arrangement of the tube elements.

In Fig. 1, the tube vessel is represented by i, which may assume any desired tubular shape. The vessel is subdivided into two portions by means of an electrically insulating wall or partition 2, in which is centrally fixed a conically shaped electron emitting member 3. Member 3 may be formed of a solid or gauze material which is coated with barium oxide. In the case that the structure is of gauze, the barium oxide may be filled in the interstices of the gauze wires. The base end of member 3 faces a heated pool of mercury 4, at the lower end of the tube, the discharge of which is maintained between anode electrodes 6 and l and cathode electrodeB. The ionic and electronic discharge from the mercury pool travels upwardly towards the partition member 2 and is forced thereby to act upon cone 3. The apex of the conical member is furthermore provided with a minute aperture 9, and the heated gases, traveling upwardly, are forced to pass through this aperture. The passage of the hot stream through this constriction causes a further heating of member 3, which by virtue of its coating acts as an electron emitter. Any mercury which finds itself in the upper part of the chamber may flow back into the mercury pool 4, after condensation by passing through the capillary port disposed in insulating wall 2. Although the illustrated embodiment shows the aperture directed vertically towards the anode, the same may assume other directions as well. 5

Plate element 10, having fine metallic wires H, as of nickel, projecting therefrom is suitably mounted in the upper portion of tube I. This plate assembly cooperates with the electron emitter 3. These wires serve to ease the poten- 10 tial gradient adjacent the plate and serve to prevent a kickback of the current stream as is likely when an excessive hot spot is formed on the anode. Not only do these wires cause a difierence in potential to exist between plate Ill and the tips of the wires, but they also protect, in a measure, the plate It against the effects of bombardment thereagainst of the positive ions. To aid in this effect, in order to make high operating capacities possible, and to positively and completely control the output of the tube, the plate is furthermore totally enclosed by a screen grid element I2, which is mounted upon the insulating support It, having its only opening for exit or entrance of the ionized gases or vapor in the holes of screen element l2. This support it, is made of lava or isolantite and may support the grid work of a bottom and lateral wall at the top edge of the grid. As illustrated, only the bottom portion is of a grid construction. Preferably, when the lateral wall is formed by a grid, some of the metallic wires ll protruding from the anode ill are directed towards it. External conductor i5 is connected to the plate i0 through support M. Conductor II is connected to the 5 screen grid i2, whereby suitable potentials are imposed upon the latter. This screen grid I 2 exercises a protecting function upon the anode, especially when the former has imposed upon it a negative potential.

Intermediate the electron emitting member 3 and plate and screen grid assembly lit-II, is disposed a control grid l9, which receives a suitable potential by the conducting terminal 20. If desired the lateral surface of this grid may be solid and extend down to insulator 2, and the top may be of mesh material, thereby enclosing the aperture 9 of cone 3, on the upper half of the tube. This grid serves to control the nature and extent of the space charge in the upper portion of the tube. The relative position of this grid element between the plate assembly ifl-l l and electron emitter 3 controls the potential drop experienced by the tube. With positive potentials imposed upon the control grid IS, the closer the same is placed to the plate, the lesser is the potential drop in the tubes. The converse is also true. Although this control grid is shown as cylindrical in the illustrated embodiment, the same may assume other forms in accordance with the operating characteristics desired.

The possibility of an external connection being made to cone element 3 is provided by terminal lead 2| which may be connected in an associated circuit with the other elements in a manner known in the art.

In Fig. 2 is shown a view similar to Fig. 1, in which similar parts are indicated by the same reference numerals. The difference in this modification arises in the mode of generation of the heating stream. The contact 25 acting as an auxiliary anode is connected to the cathode or negative terminal immersed in the pool of mercury 28 by means of a filament 21. The filament is cooled by the mercury at its point of contact therewith and causes the evaporation of the mercury at that point, and the direct ionization of the mercury. A smaller potential difference exists in this arrangement between the bodies 21 and 28, and a smaller amount of mercury is evaporated. However the ionization is sufiicient to activate the electron emitter 3. At the same time the hot spot is stabilized at the point of filaments 21 and the possibility of breakage from this cause is thus eliminated.

Fig. 3 illustrates in greater detail the anode and screen-grid assembly shown in Figures 1 and 2 and described in detail in conjunction with Fig. 1. The other elements shown in Fig. 3 are explained hereinafter.

Fig. 4 shows the construction of a tube which is simpler than that illustrated in Figs. 1-3 and which is adequate for operation at moderate voltages. In this construction the electron emitting cone 33 is mounted from the upper stem 34, rather than in a separate partition member as is the case with the construction illustrated in the other figures. The upper stem carries a solid tubular metallic member 35, preferably of nickel, by its top rim. The electron emitting cone 33 'is fixed in an insulating plate 36, fitted in the bottom of the tubular member, and connections therefrom to the exterior of the tube is made through conductor 38, tubular member 35 and conductor 39. The screen-grid 40 and the plate element 4|, with the wires 42 depending from the latter are mounted from a stem 44 fixed to the underside of stem 34. Connection to the screen grid is made by conductor 45, and to the plate 4| by conductor 46. The assembly thus far described is adapted to cooperate with a heating stream resulting from the auxiliary discharge of a mercury pool of either the form illustrated in Fig. 1, or else that shown in Fig. 2. Under some circumstances I have found it practicable to use an ordinary heater filament to cause the indirect heating of the electron-emitting cone elements.

Element 35 may be lengthened to meet varying operating conditions. That element as well as the other supporting elements-comprised in the assembly may be formed of glass for the purpose of effecting economies in manufacture.

.As a. further refinement for the prevention of kickback, I provide a transformer 50--5|, (Fig. 3), which is connected in one leg of the alternating current line. One winding, 50, acting as a primary, is connected to the anode at l5. The other winding, 5|, as secondary is connected to the screen grid terminal II. The operation is as follows: During rectification, one-half the alternating-current wave flowing through the primary winding 50 suppresses any current in the secondary winding 5|. During reversal, when the tube is inoperative, the collapsing lines of force in the transformer, produce a negative charge on enclosing grid II, which prevents kickback.

In the case of inversion of direct current, at the time that direct current is flowing through the primary 50 of the transformer, the voltage charge on grid I! does not interrupt the flow of the current, by virtue of the interleakage in secondary 5|. However, when the ionized gas in the tube is suppressed at the cathode grid, the rapidly collapsing lines of force produce a voltage in secondary 5| and a like heavy negative charge on grid i2, which aids in scavenging the ionized space.

The structure shown in this application will accomplish the same functions as that shown in my application Serial No. 567,735, for Power translating apparatus, filed October 8, 1931. That application discloses an electron relay for use with relatively small currents. That is, with the structure shown in that application I may rectify or invert currents of the order of telephonic currents up to as high as perhaps 400 or 500 amperes.

As stated above I may in some circumstances use an ordinary heater filament to cause the indirect heating of the electron-emitting cone elements shown in this application. This is also for use with relatively low current, that is, of the same order as the currents with which the structure shown in my earlier application will operate.

The structure disclosed in this application operates in the same manner, so far as function is concerned, as that shown in my earlier application. With the structure shown in this.application, however, I may rectify or invert small currents, such as telephonic currents, and also very heavy currents at high voltages. While I do not know the upper limit of such currents and voltages which may be handled satisfactorily, it is probable that I can handle currents of the order of several thousand amperes.

The present structure can be used for such high currents because it does not use a filament as the main current-carrying cathode, and therefore is not subject to the difficulty offilament burn-outs which are encountered with high currents when a filament alone, or an indirectly heated filamentary cathode, is used. Furthermore, with large currents the present device is more efficient than the structure shown in my earlier application.

As explained in my earlier application, a mesh grid completely enclosing a filament may be used to stop and start the flow of current between the anode and cathode of a rectifier tube by applying a small negative or positive voltage, respectively, to the grid. The same function is served by the grid IQ of this application.

As a specific example of the operation of the tubes disclosed in this application, if 500 volts D. C. is applied across the anode l0 and cathode 3, with a resistance of 50 ohms in the line, the tube will pass approximately 9 amperes of current, and this current may be started and stopped with approximately 10 volts positive and 10 volts negative applied to the grid IS. The value of this voltage will depend on the size of the openings in the mesh of the grid l9 and will be lower positively for starting and higher negatively for stopping as the openings are made larger.

Having described my invention what I claim is:

1. In a low-gas-pressure tube, an electronemitting cathode, an anode cooperating with said cathode, a plurality of closely spaced metallic wires fixed to said anode and a protective screengrid totally enclosing said anode and attached wires, said wires pointing towards said grid struc-- ture.

2. In the combination claimed in claim 1 wherein said cathode consists of a conically shaped hollow member with its apex disposed toward said anode adapted to be heated by a hot stream of ionized gas passing from the base thereof through said apex.

3. In a low-gas-pressure tube, an electronemitting cathode at one end of the tube, a supporting member in axial alignment with said cathode at the other end of the tube, an anode extending from said support, a plurality of closely spaced metallic wires fixed to said anode, and a protective screen-grid totally enclosing said anode and attached wires carried by said supporting member.

a. ,An electronic relay consisting of two chambers, an insulating partition for defining said chambers, a mercury discharge device disposed at the lower end of one of said chambers, an electron emitting cathode fixed in said partition having a flaring interior surface directed towards said mercury discharge device, said interior surface terminating in an aperture disposed in the lower end of the second chamber, an anode at the upper end of said second chamber, and a protective screen grid totally enclosing said anode.

5. In the combination claimed in claim 4, wherein a plurality of closely spaced metallic Wires extend from said anode towards said cathode.

6. In the combination claimed in claim 4, wherein a control grid is disposed in said second chamber between said cathode and said screen grid.

7. In the combination claimed in claim 4. wherein said mercury discharge device comprises a pool of mercury, a negative terminal immersed in said pool of mercury, an auxiliary anode above said pool, and a conducting member connected between said auxiliary anode and said negative terminal.

8. In a low-gas-pressure tube, a mercury discharge device disposed at the lower end of said tube, a supporting member at the upper end of said tube, an anode disposed upon the lower side of said member, a plurality of metallic wires extending from said anode, a screen-grid totally enclosing said anode and attached wires, a tubular enclosure depending from said supporting member for said anode and screen grid assembly comprising an insulating plate at the bottom thereof, and an electron-emitting cathode in said insulating plate having a constricted passage through which the products of the mercury vapor discharge device are adapted to pass.

9. A discharge device comprising a sealed container, a pool of mercury in the base of said container, an anode mounted within said container, an additional metallic electron-emitting element having an opening therein mounted between said mercury pool and anode and a controlgrid surrounding said element interposed between the opening in said element and said anode.

, 10. A discharge device comprising a sealed container, a mercury pool within said container, an

anode mounted within said container, an additional thermionic element consisting of a perforated electron-emitting cathode located between said mercury pool and said anode, and a grid surrounding said cathode and interposed between said perforations and said anode for controlling current flow to said anode.

11. A discharge device comprising a sealed container, a mercury pool within said container, an anode mounted within said container, a perforated electron-emitting cathode located between said mercury pool and said anode and a grid adjacent said cathode and interposed between said perforations and said anode for controlling current flow to said anode, a metallic screen mounted adjacent said anode.

12. A discharge device comprising a sealed container, a vaporizable cathode within said container, means for causing the vaporization of said cathode, an anode mounted within said container,

an additional cathode adapted to be brought to a condition of high emissivity by vapor from said first mentioned cathode, mounted between said vaporizable cathode and said anode, and a control grid mounted within said container, said control grid being mounted adjacent said cathode of high emissivity and in the path of current flow from said last mentioned cathode to said anode.

13. A discharge device comprising a sealed container, a vaporizable cathode in the base of said container, an anode mounted within said container, an additional metallic electron-emitting element having an opening therein mounted between said cathode and anode, and a control grid interposed between the opening in said element and said anode.

14. A discharge device comprising a sealed container, a vaporizable cathode within said container, an anode mounted within said container, an additional perforated electron-emitting cathode located between said vaporizable cathode and said anode, and a grid adjacent said additional cathode and interposed between said perforations and said anode for controlling current flow to said anode.

15. A discharge device comprising a sealed container, a vaporizable cathode within said container. an anode mounted within said container, an additional perforated electron-emitting cathode located between said cathode and said anode, and a grid adjacent said additional cathode and interposed between said perforations and said anode for controlling current flow to said anode, a metallic screen mounted adjacent said anode.

16. A discharge device comprising a sealed container, a vaporizable cathode within said container, means for causing the vaporization of said cathode, an anode mounted within said container, a gauze-like cathode of relatively high emissivity mounted between said vaporizable cathode and said anode, and a control grid mounted within said container, said control grid being mounted adjacent said cathode of high emissivity and in the path of current flow from said last mentioned cathode to said anode.

17. A discharge device comprising a sealed container, a pool of mercury in the base of said container, an anode mounted within said container, a metallic conical-shaped element having an opening, therein mounted between said mercury pool and plate, and a control grid interposed be tween the opening in said element and said anode.

18. A discharge device comprising a sealed container, a vaporizable cathode within said conill tainer, an anode mounted within said container, a perforated inverted cone-shaped electron-emitting cathode located between said cathode and said anode, and a grid adjacent said cathode and interposed between said perforations and said anode for controlling current flow to said anode.

19. A discharge device comprising a sealed container, a vaporizable cathode within said container, a perforated inverted cone-shaped electron-emitting cathode located between said cathode and said anode, and a grid adjacent said cathode and interposed between said perforations and said anode for controlling current flow to said anode, a metallic screen mounted adjacent said anode.

20. A discharge device comprising a sealed container, a vaporizable cathode within said container, means for causing the vaporization of said cathode, an anode mounted within said container, a gauze-like cathode coated with material of high emissivity mounted between said vaporizable cathode and said anode, and a control grid mounted within said container, said control grid being mounted adjacent said cathode of high emissivity and in the path oi current flow from said last mentioned cathode to said anode.

21. In a low-gas-pressure tube, two electronemitting cathodes, an anode cooperating with both of said cathodes, and a protective screen grid enclosing and concentrating the current flow through one of said cathodes.

22. In a low-gas-pressure tube, two electronemitting cathodes, an anode cooperating with both of said cathodes, and a protective screen grid enclosing one of said cathodes.

23. In a low-gas-pressure tube, two cooperative electron-emitting cathodes, one being supplementary, an anode cooperating with both of said I cathodes, a protective screen g'rid enclosing said supplementary cathode, and a protective screen grid totally enclosing said anode.

24. In a low-gas-pressure tube, two cooperative electron-emitting cathodes, one being supplementary, an anode cooperating with both of said cathodes, a protective screen grid enclosing said supplementary cathode, a protective screen grid enclosing said anode, and both grids cooperating to start or stop the action of the tube.

25. In a low-gas-pressure tube, two cooperative electron-emitting cathodes, an anode cooperating with both of said cathodes, a protective screen grid enclosing said supplementary cathode, a protective screen grid enclosing said anode, and both grids cooperating to increase or decrease resistance of the tube to current flow.

26. In a low-gas-pressure tube, electron-emitting cathode, an additional cooperative electronemitting cathode, an anode cooperating with said cathode, a control grid enclosing said additional electron-emitting cathode, and a protective screen grid totally enclosing said anode.

27. In a low-gas-pressure tube, an electronemitting cathode, a means to concentrate the current flow, an anode cooperating with said cathode, an additional supplementary and cooperative cathode operated by the concentration of the current flow and a control screen adjacent to said cathode.

28. In a low-gas-pressure tube, an electronemitting cathode, a means of concentrating the current flow, an anode cooperating with said cathode, a controlling screen grid enclosing said anode, a control grid disposed adjacent an additional supplementary and cooperative cathode, said additional cathode so disposed as to become electronically emittive by the concentration of the current flow, both grids adapted to be simultaneously energized to control the output or input of the tube.

29. In a discharge device comprising a sealed container, a vaporizable cathode within said container, means for causing the vaporization of said cathode, a separate container within said sealed container, an anode mounted within said separate container, having a current flow concentrating and an electron-emitting auxiliary cathode attached to said separate container, and a grid to control the current flow within said separate container.

30. In a discharge device comprising a sealed container, a vaporizable cathode within said container, means for causing the vaporization of said cathode, a separate container within said sealed container, an anode mounted within said separate container having an electron-emitting auxiliary cathode attached to said separate container, said anode cooperating with both the vaporizable cathode and auxiliary cathode and a grid within said separate container to control the flow 01 current.

31. In a low-gas-pressure tube containing two electron-emitting cathodes within a single chamher, a means whereby the electron-emission of one cathode controls the electron emission of the other.

32. A discharge device comprising a sealed envelope, a chamber within said device, an activating cathode within said device .but outside said chamber, and an anode and an auxiliary cathode within said chamber.

33. A discharge device comprising a sealed envelope, a chamber within said device, an activating cathode within said device but outside said chamber, and an anode, a'grid, and an auxiliary cathode within said chamber.

34. A discharge device comprising a sealed envelope containing a vaporizable alkali metal in a rarefied atmosphere, an exciting cathode at one end of said device, a separate chamber at the other end of said device, and an anode, a control grid, and a solid cathode within said chamber.

35. A discharge device comprising a sealed envelope containing an alkali metal vapor in a rarefled atmosphere, an activating cathode, a solid main cathode, an anode, and means by which the vapor, ionized by the activating cathode, is forced to pass through the solid main cathode to reach the anode.

36. A discharge device comprising a sealed envelope containing a vaporizable alkali metal, an inner chamber containing an anode, a control screen grid and a solid cathode, and an activating cathode at the other end of said envelope from said chamber.

37. In a low-gas-pressure tube, two electron emitting cathodes, an anode cooperating with both of said cathodes, a protective screen grid enclosing one of said cathodes, insulating means between the other of said cathodes and said anode, and a vent in said insulating means.

38. An alkali metal are discharge tube containing a first cathode and an anode, a partition separating said cathode and anode, said partition having a vent to permit the return of alkali metal SYDNEY N. BARUCH. 

